Embodiments of the invention relate to a thin film transistor liquid crystal display and a manufacturing method thereof.
Thin film transistor liquid crystal displays (TFT-LCDs) have advantages such as small volume, low power consumption, and free of radiation, and have prevailed in the current flat panel display market. Currently, the manufacturing method of a TFT-LCD mainly employs a five-patterning process and a four-pattern process. The five-patterning process comprises patterning of a gate line and a gate electrode, patterning of an active layer, patterning of source/drain electrodes, patterning of a through hole, and patterning of a pixel electrode. The four-patterning process comprises a step combining patterning of the active layer and patterning of the source/drain electrode into a single patterning process by using a half-tone or a grey tone mask based on the five-patterning process.
A half-tone or a grey tone mask is provided with a completely transparent region, a partially transparent region and a non-transparent region. For example, the non-transparent region corresponds to a region where the source electrode and the drain electrode are located, the partially transparent region corresponds to a region where the TFT channel region pattern is located, and the completely transparent region corresponds to a region other than the above regions. In practice, in order to prevent ultraviolet light from passing through the completely transparent region into the TFT channel region, the width of the drain electrode is increased so as to ensure the etching quality of the TFT channel region. However, this increases the size of the drain electrode in the thin film transistor, and therefore causes the technical drawbacks such as small effective light transmitting area and low aperture ratio.